Rod rotator assembly for an artificial lift system

ABSTRACT

A rod rotator assembly for an artificial lift system includes a housing configured to be supported by a carrier of the artificial lift system. The rod rotator assembly also includes a top cap configured to rotate relative to the housing, in which the top cap is configured to support a polish rod of the artificial lift system. In addition, the rod rotator assembly includes a load cell disposed within the housing. The load cell is configured to support the top cap, and the load cell is configured to output a sensor signal indicative of a load applied by the polish rod to the housing.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from and the benefit of U.S.Provisional Application Ser. No. 63/140,672, entitled “ROD ROTATORASSEMBLY FOR AN ARTIFICIAL LIFT SYSTEM”, filed Jan. 22, 2021, which ishereby incorporated by reference in its entirety.

BACKGROUND

The present disclosure relates generally to a rod rotator assembly foran artificial lift system.

Wells are drilled into reservoirs to discover and produce oil. The oilwithin the reservoirs may be under sufficient pressure to drive the oilthrough the well to the surface. However, over time, the naturalpressure of the oil may decline, and an artificial lift system may beused to extract the oil from the reservoir. The artificial lift systemmay include a pump disposed within the reservoir and a wellhead at thesurface. A tubing string may be supported by the wellhead and may extendto the reservoir, and the pump may drive the oil from the reservoir tothe wellhead via the tubing string.

The pump is driven by a series of polish rods that extend through thetubing string to the pump. The polish rods are lifted and lowered by apump jack, which supports the polish rods. The repeated lifting andlowering movement of the polish rods causes the polish rods to wear atthe point(s) of contact with the tubing string. Accordingly, certainartificial lift systems include a rod rotator to drive the polish rodsto rotate within the tubing string, thereby distributing the wear aroundthe circumference of the polish rods. As a result, the longevity of thepolish rods may be increased.

Certain artificial lift systems include a load cell configured tomonitor the load on the polish rods. If the load on the polish rods isoutside of a target range (e.g., above a maximum threshold load or belowa minimum threshold load), an operator may adjust or terminate operationof the artificial lift system. In certain artificial lift systems, theload cell is disposed about a top polish rod and positioned between therod rotator and a carrier, which is coupled to the pump jack by cablesand supports the rod rotator. To substantially reduce the non-verticalload applied to the top polish rod due to misalignment of the rodrotator and the load cell, a first set of alignment plates may bedisposed between the rod rotator and the load cell. In addition, tosubstantially reduce the non-vertical load applied to the top polish roddue to misalignment of the load cell and the carrier, a second set ofalignment plates may be disposed between the load cell and the carrier.Unfortunately, the load cell and the two sets of alignment platesincreases the height of the stack of equipment supported by the pumpjack, which increases the stroke length of the pump jack.

BRIEF DESCRIPTION

In certain embodiments, a rod rotator assembly for an artificial liftsystem includes a housing configured to be supported by a carrier of theartificial lift system. The rod rotator assembly also includes a top capconfigured to rotate relative to the housing, in which the top cap isconfigured to support a polish rod of the artificial lift system. Inaddition, the rod rotator assembly includes a load cell disposed withinthe housing. The load cell is configured to support the top cap, and theload cell is configured to output a sensor signal indicative of a loadapplied by the polish rod to the housing.

DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a schematic side view of an embodiment of an artificial liftsystem having an embodiment of a rod rotator assembly;

FIG. 2 is a schematic side view of a portion of the artificial liftsystem of FIG. 1, including a wellhead and a polish rod connectionassembly;

FIG. 3 is a schematic side view of the polish rod connection assembly ofFIG. 2, in which the polish rod connection assembly includes the rodrotator assembly;

FIG. 4 is a schematic cross-sectional view of the rod rotator assemblyof FIG. 3; and

FIG. 5 is a cross-sectional perspective view of the rod rotator assemblyof FIG. 3.

DETAILED DESCRIPTION

One or more specific embodiments of the present disclosure will bedescribed below. In an effort to provide a concise description of theseembodiments, all features of an actual implementation may not bedescribed in the specification. It should be appreciated that in thedevelopment of any such actual implementation, as in any engineering ordesign project, numerous implementation-specific decisions must be madeto achieve the developers' specific goals, such as compliance withsystem-related and business-related constraints, which may vary from oneimplementation to another. Moreover, it should be appreciated that sucha development effort might be complex and time consuming, but wouldnevertheless be a routine undertaking of design, fabrication, andmanufacture for those of ordinary skill having the benefit of thisdisclosure.

When introducing elements of various embodiments of the presentdisclosure, the articles “a,” “an,” “the,” and “said” are intended tomean that there are one or more of the elements. The terms “comprising,”“including,” and “having” are intended to be inclusive and mean thatthere may be additional elements other than the listed elements. Anyexamples of operating parameters and/or environmental conditions are notexclusive of other parameters/conditions of the disclosed embodiments.

FIG. 1 is a schematic side view of an embodiment of an artificial liftsystem 10 having an embodiment of a rod rotator assembly 12. Asillustrated, the artificial lift system 10 includes a pump 14 disposedwithin a reservoir 16. The artificial lift system 10 also includes awellhead 18 at the surface 20. A tubing string 22, which is supported bythe wellhead 18, extends from the surface 20 to the reservoir 16. Thepump 14 is configured to drive oil from the reservoir 16 to the surface20 via the tubing string 22 and the wellhead 18.

The pump 14 is driven by a series of polish rods that extend through thetubing string 22 to the pump 14. As illustrated, a polish rod 24 at theend of the series of polish rods is coupled to a pump jack 26 of theartificial lift system 10. The pump jack 26 is configured to lift andlower the polish rods, thereby driving the pump 14. One or more polishrods may contact the tubing string 22 at one or more points along acircumference of the polish rod(s). Accordingly, as the polish rods aredriven to move within the tubing string 22, certain point(s) on thepolish rod(s) may wear. The rod rotator assembly 12 is configured todrive the polish rods to rotate within the tubing string 22, therebydistributing the wear around the circumference of the polish rod(s). Asa result, the longevity of the polish rods may be increased. Asdiscussed in detail below, the rod rotator assembly 12 is supported by acarrier (e.g., carrier bar) that is supported by the pump jack 26 viaone or more cables.

In certain embodiments, the rod rotator assembly 12 includes a housingconfigured to be supported by the carrier of the artificial lift system10. In addition, the rod rotator assembly 12 includes a top capconfigured to rotate relative to the housing, in which the top cap isconfigured to support the polish rod 24 (e.g., via a polish rod clamp).The rod rotator assembly 12 also includes a load cell disposed withinthe housing (e.g., between the top cap and a base of the housing). Theload cell is configured to support the top cap, and the load cell isconfigured to output a sensor signal indicative of a load applied by thepolish rod to the housing. Accordingly, load on the polish rods may bemonitored (e.g., continuously, periodically, on demand, etc.) tofacilitate operation of the artificial lift system 10. For example,operation of the pump jack 26 may be adjusted or terminated (e.g.,automatically or manually) in response to the load on the polish rodsbeing outside of a target range (e.g., above a maximum threshold load orbelow a minimum threshold load). Because the load cell is disposedwithin the rod rotator assembly housing, the height of the stacksupported by the carrier may be reduced (e.g., as compared to aconfiguration in which a load cell is positioned between the rod rotatorand the carrier, a first set of alignment plates is positioned betweenthe rod rotator and the load cell, and a second set of alignment platesis positioned between the load cell and the carrier), thereby reducingthe stroke length of the pump jack. In addition, the number of componentinterfaces along the polish rod may be reduced (e.g., as compared to aconfiguration in which a load cell is positioned between the rod rotatorand the carrier, a first set of alignment plates is positioned betweenthe rod rotator and the load cell, and a second set of alignment platesis positioned between the load cell and the carrier), thereby reducingthe possibility of misalignment of components at the interfaces.

FIG. 2 is a schematic side view of a portion of the artificial liftsystem 10 of FIG. 1, including the wellhead 18 and a polish rodconnection assembly 28. In the illustrated embodiment, the wellhead 18includes a tubing spool 30 that supports the tubing string (e.g., via atubing hanger coupled to an end of the tubing string and engaged withthe tubing spool). The wellhead 18 also includes a pumping tee 32coupled to the tubing spool 30 and to a flowline 34. The pumping tee 32is configured to receive oil from the tubing spool 30 and to control theflow of the oil through the flow line 34. The flow line 34 may extend toa storage or processing facility. Furthermore, the wellhead 18 includesa stuffing box 36 coupled to the pumping tee 32. The stuffing box isconfigured to establish a seal around the polish rod 24 thatsubstantially blocks flow of oil through the polish rod/stuffing boxinterface while enabling the upward/downward movement of the polish rod.While the wellhead 18 includes the tubing spool 30, the pumping tee 32,and the stuffing box 36 in the illustrated embodiment, the wellhead mayinclude other and/or additional components in other embodiments.

As discussed in detail below, the polish rod connection assembly 28includes the rod rotator assembly 12, which is configured to drive thepolish rod 24 to rotate relative to the wellhead 18 and the tubingstring. The polish rod connection assembly 28 also includes a carrier 38(e.g., carrier bar) configured to support the rod rotator assembly 12.The carrier 38 may be coupled to the pump jack by one or more cables. Inaddition, the polish rod connection assembly 28 includes one or morepolish rod clamps 40 configured to non-movably couple to the polish rod24. The polish rod clamps 40 transfer the load (e.g., substantiallyvertical load) of the polish rods to the rod rotator assembly 12, theload flows through the rod rotator assembly 12 to the carrier 38, andthe load applied to the carrier is transferred to the pump jack via thecable(s). Accordingly, during an upward movement of the pump jack, thepump jack lifts the carrier 38 via the cable(s), the carrier 38 drivesthe rod rotator assembly 12 to move upwardly, and the rod rotatorassembly 12 drives the polish rods to move upwardly via engagement ofthe rod rotator assembly 12 with the polish rod clamp(s). During adownward movement of the pump jack, the pump jack drives the polish rod24 downwardly. Because the polish rod clamp(s) 40 are non-movablycoupled to the polish rod 24, the polish rod clamp(s) 40 drive the rodrotator assembly 12 to move downwardly, thereby driving the carrier 38to move downwardly.

FIG. 3 is a schematic side view of the polish rod connection assembly 28of FIG. 2. As previously discussed, the polish rod connection assembly28 includes the rod rotator assembly 12, the carrier 38, and the polishrod clamps 40. In the illustrated embodiment, the rod rotator assembly12 includes a housing 42, which is supported by the carrier 38. The rodrotator assembly 12 also includes a top cap 44 configured to rotaterelative to the housing 42. As illustrated, the top cap 44 is engagedwith the polish rod clamp(s) 40, thereby supporting the polish rods. Inaddition, due to the engagement of the top cap 44 with the polish rodclamp(s) 40, rotation of the top cap 44 relative to the housing 42drives the polish rods to rotate, thereby increasing the longevity ofthe polish rods. While the polish rod connection assembly 28 includestwo polish rod clamps 40 in the illustrated embodiment, in otherembodiments, the polish rod connection assembly may include more orfewer polish rod clamps (e.g., 1, 3, 4, or more).

In the illustrated embodiment, the rod rotator assembly 12 includes alever 46 configured to drive the top cap to rotate. In certainembodiments, the lever 46 is coupled to a worm gear of the rod rotatorassembly 12, and movement of the lever drives the worm gear to rotate.As discussed in detail below, the worm gear is engaged with a main gearof the rod rotator assembly 12 and configured to drive the main gear torotate. The main gear, in turn, is non-rotatably coupled to the top cap44. Accordingly, movement of the lever 46 drives the top cap 44 torotate, thereby driving the polish rods to rotate via contact betweenthe top cap 44 and the polish rod clamps 40. The lever 46 may be drivento move via a cable extending between the lever 46 and a base of thepump jack. As the rod rotator assembly 12 moves upwardly and downwardlywith the polish rod during operation of the pump jack, the cable maycyclically drive the lever 46 to move in response to the rod rotatorassembly 12 moving to a distance away from the pump jack cable anchorpoint that is greater than the length of the cable. While the top plate44 is driven to rotate by the lever 46, the worm gear, and the main gearin the embodiment disclosed herein, the top plate may be driven torotate relative to the rod rotator assembly housing via any othersuitable device/assembly (e.g., electric motor, pneumatic actuator,another suitable mechanical drive assembly, etc.).

In the illustrated embodiment, a set of alignment plates 48 ispositioned between the housing 42 of the rod rotator assembly 12 and thecarrier 38 (e.g., carrier bar). The set of alignment plates 48 mayinclude a first alignment plate having a hemispherical recess and asecond alignment plate having a hemispherical protrusion. Thehemispherical protrusion of the second alignment plate is engaged withthe hemispherical recess of the first alignment plate, thereby enablingthe alignment plates to slide relative to one another. One alignmentplate of the set may be engaged with the rod rotator assembly housing42, and the other alignment plate of the set may be engaged with thecarrier 38. The set of alignment plates 48 facilitates a transfer ofload (e.g., substantially vertical load) from the rod rotator assemblyhousing 42 to the carrier 38 even while the housing 42 and the carrier38 are not aligned with one another (e.g., the bottom surface of thehousing 42 is not parallel to the top surface of the carrier 38).Accordingly, the non-vertical load (e.g., load that is not along thedirection of extension/movement of the polish rod 24) applied to thepolish rod 24 at the interface between the housing 42 and the carrier 38may be substantially reduced, thereby increasing the longevity of thepolish rod 24. While a set of alignment plates having a hemisphericalprotrusion/hemispherical recess is disclosed above, the set of alignmentplates may have another suitable arrangement that facilitates transferof load (e.g., substantially vertical load) from the rod rotator housingto the carrier while substantially reducing the non-vertical loadapplied to the polish rod due to misalignment of the housing/carrier.Furthermore, in certain embodiments, the set of alignment plates may beomitted.

FIG. 4 is a schematic cross-sectional view of the rod rotator assembly12 of FIG. 3. As previously discussed, the rod rotator assembly 12includes the housing 42 and the top cap 44. The housing 42 is configuredto be supported by the carrier, and the top cap 44 is configured torotate relative to the housing 42. The top cap 44 is also configured tosupport the polish rod via the polish rod clamp(s). In the illustratedembodiment, the rod rotator assembly 12 also includes a load cell 50, abearing 52, and the main gear 54 disposed within the housing 42. Themain gear 54 is non-rotatably coupled to the top cap 44 and configuredto be driven to rotate by a worm gear or an electrical rotary motor. Inaddition, the load cell 50 is disposed within the housing 42 (e.g.,between the top cap 44 and a base 56 of the housing 42). The load cell50 is configured to support the top cap 44, and the load cell 50 isconfigured to output a sensor signal indicative of a load applied by thepolish rod to the housing 42. As illustrated, the bearing 52 is disposedbetween the load cell 50 and the main gear 54, thereby enabling the maingear 54 to rotate relative to the load cell 50, which may benon-rotatably coupled to the housing 42. However, in other embodiments,the load cell may be non-rotatably coupled to the main gear. In suchembodiments, the bearing may be disposed between the load cell and thebase of the housing. As used herein, “disposed between” refers to anarrangement in which one component is positioned between at least aportion of another component and at least a portion of a furthercomponent.

While the rod rotator assembly 12 includes a single bearing 52 in theillustrated embodiment, in other embodiments, the rod rotator assemblymay include more or fewer bearings (e.g., 0, 2, 3, or more). Inaddition, in certain embodiments, one or more bushings may be disposedbetween components within the rod rotator assembly housing (e.g., aloneor in combination with the bearing(s)). For example, the bearing may beomitted, and a bushing may be disposed between the main gear and theload cell. Furthermore, while the top cap 44 is driven to rotate by themain gear 54 in the illustrated embodiment, in other embodiments, thetop cap may be driven to rotate by any other suitable device/assembly(e.g., in which at least a portion of the device/assembly is disposedwithin the housing between the top cap and the load cell). For example,in certain embodiments, an electrical rotary motor (e.g., gimbaled ornon-gimbaled) may be disposed between the load cell and the top cap. Insuch embodiments, a first portion (e.g., body) of the motor may benon-rotatably and translatably coupled to the housing, and a secondportion (e.g., rotary shaft) may be non-rotatably coupled to the top capto drive the top cap to rotate. Furthermore, in such embodiments, themain gear, the worm gear, the lever, and the bearing may be omitted.

Because the load cell 50 is positioned between the top cap 44 and aportion (e.g., base 56) of the housing 42, the load applied by thepolish rods to the top cap 44 is transferred through the load cell 50 tothe housing 42, which is supported by the carrier. Accordingly, the loadon the polish rods may be monitored by the load cell (e.g.,continuously, periodically, on demand, etc.) to facilitate operation ofthe artificial lift system 10. For example, operation of the pump jackmay be adjusted or terminated (e.g., automatically or manually) inresponse to the load on the polish rods being outside of a target range(e.g., above a maximum threshold load or below a minimum thresholdload). The load cell may output the sensor signal indicative of the loadapplied by the polish rods to the housing 42 via a wired or wirelessconnection. In the illustrated embodiment, a load cell cable 58 extendsbetween the load cell and a monitoring/control system, and the sensorsignal may be output via the load cell cable 58. However, in otherembodiments, the load cell may be communicatively coupled to themonitoring/control system via a wireless connection. The wirelessconnection may utilize any suitable wireless communication protocol,such as Bluetooth, WiFi, radio frequency identification (RFID), aproprietary protocol, or a combination thereof. Furthermore, the loadcell 50 may include any suitable sensor(s) configured to monitor theload on the polish rods, such as piezoelectric sensor(s), straingauge(s), other suitable type(s) of sensor(s), or a combination thereof.

Because the load cell is disposed within the rod rotator assemblyhousing, the height of the stack supported by the carrier may be reduced(e.g., as compared to a configuration in which a load cell is positionedbetween the rod rotator and the carrier, a first set of alignment platesis positioned between the rod rotator and the load cell, and a secondset of alignment plates is positioned between the load cell and thecarrier). Accordingly, the stroke length of the pump jack may bereduced. In addition, the number of component interfaces along thepolish rod may be reduced (e.g., as compared to a configuration in whicha load cell is positioned between the rod rotator and the carrier, afirst set of alignment plates is positioned between the rod rotator andthe load cell, and a second set of alignment plates is positionedbetween the load cell and the carrier). As a result, the possibility ofmisalignment of components at the interfaces may be reduced. While a setof alignment plates is not disposed within the housing in theillustrated embodiment, in other embodiments, at least one set ofalignment plates may be disposed within the housing (e.g., between themain gear and the load cell).

FIG. 5 is a cross-sectional perspective view of the rod rotator assembly12 of FIG. 3. As previously discussed, the rod rotator assembly 12includes a housing 42, which is supported by the carrier. In theillustrated embodiment, the housing 42 includes the base 56 and a body60 extending upwardly from the base 56 along a longitudinal axis 62 ofthe rod rotator assembly 12. The body 60 forms a first opening 64 on anopposite longitudinal side of the housing 42 from the base 56, and thefirst opening 64 provides access to an interior 66 of the housing 42.Furthermore, in the illustrated embodiment, the base 56 of the housing42 forms a second opening 68. The openings in the housing 42 facilitatepassage of the polish rod through the housing 42. In the illustratedembodiment, an annular bushing 70 is disposed within the second opening68. The annular bushing 70 is configured to contact the polish rod,thereby substantially blocking dirt and/or debris from entering thehousing interior 66 via the second opening 68. While the housing 42includes the annular bushing 70 in the illustrated embodiment, in otherembodiments, the annular bushing may be omitted. Furthermore, while thehousing 42 has an annular shape in the illustrated embodiment, in otherembodiments, the housing may have any other suitable shape (e.g.,polygonal, elliptical, irregular, etc.).

Furthermore, as previously discussed, the rod rotator assembly 12includes a top cap 44 configured to rotate relative to the housing 42.The top cap 44 is configured to rotate along a circumferential axis 72of the rod rotator assembly 12. Furthermore, as previously discussed,the top cap 44 is configured to support the polish rods via the polishrod clamp(s). In the illustrated embodiment, the top cap 44 includes abody 74 and a platform 76. The body 74 extends through the first opening64 in the housing 42 into the interior 66 of the housing 42, and theplatform 76 has an engagement surface 78 configured to engage the polishrod clamp(s), thereby supporting the polish rods. In the illustratedembodiment, the platform 76 of the top cap 44 has an opening 80configured to facilitate passage of the polish rod (e.g., top polishrod) through the platform 76. In addition, the body 74 of the top cap 44is configured to be disposed outwardly from the polish rod along aradial axis 82 of the rod rotator assembly 12, thereby facilitatingpassage of the polish rod through the body 74. While the body 74 of thetop cap 44 extends through the first opening 64 of the housing 42 intothe interior 66 of the housing 42 in the illustrated embodiment, inother embodiments, the body may not extend into the housing interior(e.g., the body may be non-rotatably coupled to a component of the rodrotator assembly positioned at least partially outside of the housing,such as the main gear). Furthermore, in certain embodiments, the body ofthe top cap may be omitted (e.g., the platform of the top cap may benon-rotatably coupled to a component of the rod rotator assembly, suchas the main gear).

In the illustrated embodiment, the rod rotator assembly 12 includes amain gear 54 non-rotatably coupled to the body 74 of the top cap 44. Themain gear 54 may be non-rotatably coupled to the body 74 of the top cap44 via any suitable type(s) of connection(s), such as weldedconnection(s), a press-fit connection, fastener connection(s), adhesiveconnection(s), other suitable type(s) of connection(s), or a combinationthereof. As previously discussed, the main gear 54 is configured to bedriven to rotate by a worm gear. In the illustrated embodiment, movementof the lever 46 drives the worm gear to rotate, thereby driving the maingear 54 to rotate. Due to the non-rotatable coupling between the maingear 54 and the body 74 of the top cap 44, rotation of the main gear 54drives the top cap 44 to rotate, thereby driving the polish rods torotate via the contact between the engagement surface 78 of the top cap44 and the polish rod clamp(s). While the main gear 54 is driven torotate by a worm gear coupled to the lever 46 in the illustratedembodiment, in other embodiments, the main gear may be driven to rotateby a motor (e.g., electric motor, hydraulic motor, pneumatic motor,etc.). Furthermore, in certain embodiments, the main gear may beomitted, and a motor (e.g., electric motor, hydraulic motor, pneumaticmotor, etc.) may drive the top cap to rotate, as discussed above withreference to FIG. 4.

In addition, as previously discussed, the rod rotator assembly 12includes a load cell 50, which is disposed within the interior 66 of thehousing 42. The load cell 50 is configured to support the top cap 44,and the load cell 50 is configured to output a sensor signal indicativeof a load applied by the polish rods to the housing 42. Because the loadcell 50 is positioned between the top cap 44 and a portion (e.g., base56) of the housing 42, the load applied by the polish rods to the topcap 44 is transferred through the load cell 50 to the housing 42, whichis supported by the carrier. Accordingly, the load on the polish rodsmay be monitored by the load cell (e.g., continuously, periodically, ondemand, etc.) to facilitate operation of the artificial lift system 10.Furthermore, as previously discussed, the load cell 50 may include anysuitable sensor(s) configured to monitor the load on the polish rod,such as piezoelectric sensor(s), strain gauge(s), other suitable type(s)of sensor(s), or a combination thereof.

In the illustrated embodiment, the rod rotator assembly 12 includes abearing 52 disposed between the load cell 50 and the main gear 54 alongthe longitudinal axis 62 of the rod rotator assembly 12. The bearing 52enables the main gear 54 to rotate relative to the load cell 50, whichmay be non-rotatably coupled to the housing 42. In the illustratedembodiment, the bearing 52 includes a ball bearing (e.g., includingmultiple bearing balls between two races). However, in otherembodiments, the bearing may include other suitable type(s) ofbearing(s) (e.g., alone or in combination with one or more ballbearings), such as roller bearing(s), fluid bearing(s), other suitabletype(s) of bearing(s), or a combination thereof. Furthermore, while therod rotator assembly 12 includes a single bearing 52 in the illustratedembodiment, in other embodiments, the rod rotator assembly may includemore or fewer bearings (e.g., 0, 2, 3, 4, or more).

In the illustrated embodiment, the body 74 of the top cap 44 overlapsthe main gear 54, the bearing 52, and a portion of the load cell 50along the longitudinal axis 62. In addition, the body 74 of the top cap44 includes a ledge 84 (e.g., annular ledge) engaged with the main gear54. As illustrated, the main gear 54 is disposed between the ledge 84 ofthe body 74 of the top cap 44 and the bearing 52 along the longitudinalaxis 62 of the rod rotator assembly 12. Accordingly, the load applied bythe polish rods to the top cap 44 is transferred to the main gear 54 viathe ledge 84, to the bearing 52 via the main gear 54, to the load cell50 via the bearing 52, and to the housing 42 via the load cell 50.Accordingly, the load applied by the polish rods is transferred throughthe load cell 50, thereby enabling the load cell to monitor the loadapplied by the polish rods to the housing 42. In embodiments in whichthe main gear and/or the bearing is omitted, the load may be transferredfrom the ledge to the load cell via another suitable path (e.g., throughthe main gear alone, through a bushing, through a motor, etc.).Furthermore, while the body of the top cap engages a correspondingcomponent of the rod rotator assembly (e.g., the main gear, a motor,etc.) via the ledge in the embodiments disclosed above, in certainembodiments, the body of the top cap may engage the correspondingcomponent via another suitable surface of the body (e.g., a bottomsurface of the body, etc.). In such embodiments, the ledge may beomitted. In addition, in certain embodiments, the body of the top capmay be omitted, and the platform of the top cap may engage thecorresponding component of the rod rotator assembly.

In the illustrated embodiment, the load cell 50 is disposed between thebody 74 of the top cap 44 (e.g., the ledge 84 of the body 74 of the topcap 44) and the base 56 of the housing 42. Accordingly, the load appliedby the polish rods to the top cap 44 is transferred through the loadcell 50 to the base 56 of the housing 42. While the load cell 50 issupported by the base 56 of the housing 42 in the illustratedembodiment, in other embodiments, the load cell may be supported byanother suitable portion of the housing. For example, in certainembodiments, the body of the housing may include a ledge, and the loadcell may be supported by the ledge. In such embodiments, the loadapplied by the polish rods to the top cap may be transferred through theload cell to the housing via the ledge. Furthermore, in certainembodiments, the load cell may be coupled to the body of the housing byany suitable type(s) of connection(s), such as fastener connection(s),adhesive connection(s), a press fit connection, other suitable type(s)of connection(s), or a combination thereof. Additionally oralternatively, the load cell may be coupled to the body of the housingvia one or more protrusion/recess interfaces. In embodiments in whichthe load cell is coupled to the body of the housing, the body supportsthe load cell, and the load applied by the polish rods to the top capmay be transferred through the load cell to the body of the housing.

In the illustrated embodiment, the rod rotator assembly 12 includes anadapter ring 86 disposed between the body 74 of the top cap 44 and theload cell 50 along the radial axis 82 of the rod rotator assembly 12.The adapter ring 86 is configured to substantially block radial movementof the top cap body 74 relative to the load cell 50 and to facilitateestablishment of a seal between the top cap body 74 and the load cell 50(e.g., to substantially block dirt and/or debris from entering a cavitybetween the top cap body and the housing body). In the illustratedembodiment, a first seal 88 (e.g., o-ring, etc.) is disposed between theadapter ring 86 and the top cap body 74, and a second seal 90 (e.g.,o-ring, etc.) is disposed between the adapter ring 86 and the load cell50, thereby establishing the seal between the top cap body 74 and theload cell 50. While the rod rotator assembly includes two seals at theadapter ring in the illustrated embodiment, in other embodiments, therod rotator assembly may include more or fewer seals at the adapter ring(e.g., 0, 1, 3, 4, or more). For example, in certain embodiments, atleast one of the first and second seals may be omitted. Furthermore, inthe illustrated embodiment, the rod rotator assembly 12 includes a thirdseal 92 (e.g., o-ring, etc.) disposed between the platform 76 of the topcap 44 and the body 60 of the housing 42 along the radial axis 82. Thethird seal 92 is configured to substantially block dirt and/or debrisfrom entering the cavity between the top cap body and the housing body.While a single seal is disposed between the platform and the housingbody along the radial axis in the illustrated embodiment, in otherembodiments, more or fewer seals (e.g., 0, 2, 3, 4, or more) may bedisposed between the platform and the housing body along the radialaxis.

As previously discussed, the load cell 50 may output a sensor signalindicative of the load applied by the polish rods to the housing 42 viaa wired or wireless connection. In the illustrated embodiment, the loadcell 50 is configured to output the sensor signal via a wiredconnection, and the wired connection includes a load cell cable 58,which may extend between the load cell 50 and a monitoring/controlsystem. Furthermore, in the illustrated embodiment, the rod rotatorassembly 12 includes a connector 94 coupled to the body 60 of thehousing 42. The connector 94 is configured to establish a wiredconnection to the load cell 50. For example, the connector may includeone or more conductors electrically coupled to the load cell, and theconnector may be configured to selectively establish an electricalconnection between the conductor(s) and the load cell cable 58. In theillustrated embodiment, the connector 94 is coupled to the body 60 ofthe housing 42 via a threaded connection. However, in other embodiments,the connector may be coupled to the housing body via other suitabletype(s) of connection(s) (e.g., alone or in combination with thethreaded connection), such as adhesive connection(s), fastenerconnection(s), other suitable type(s) of connection(s), or a combinationthereof. Furthermore, while the connector is coupled to the body of thehousing in the illustrated embodiment, in other embodiments, theconnector may be coupled to another suitable portion of the housing,such as the base. In addition, while electrical connections aredisclosed above, in certain embodiments, the load cell cable may beconfigured to establish an optical connection between the load cell andthe monitoring/control system. In such embodiments, the connector may beconfigured to establish an optical connection between the load cell andthe load cell cable. Furthermore, in certain embodiments, the connectormay be omitted. In such embodiments, the load cell cable may extendthrough an opening in the housing to the load cell. In addition, aspreviously discussed, the load cell may be communicatively coupled tothe monitoring/control system via a wireless connection.

Because the load cell is disposed within the interior of the rod rotatorassembly housing, the height of the stack supported by the carrier maybe reduced (e.g., as compared to a configuration in which a load cell ispositioned between the rod rotator and the carrier, a first set ofalignment plates is positioned between the rod rotator and the loadcell, and a second set of alignment plates is positioned between theload cell and the carrier). Accordingly, the stroke length of the pumpjack may be reduced. In addition, the number of component interfacesalong the polish rod may be reduced (e.g., as compared to aconfiguration in which a load cell is positioned between the rod rotatorand the carrier, a first set of alignment plates is positioned betweenthe rod rotator and the load cell, and a second set of alignment platesis positioned between the load cell and the carrier). As a result, thepossibility of misalignment of components at the interfaces may bereduced. While a set of alignment plates is not disposed within theinterior of the housing in the illustrated embodiment, in otherembodiments, at least one set of alignment plates may be disposed withinthe interior of the housing (e.g., between the main gear and the loadcell).

While only certain features have been illustrated and described herein,many modifications and changes will occur to those skilled in the art.It is, therefore, to be understood that the appended claims are intendedto cover all such modifications and changes as fall within the truespirit of the disclosure.

The techniques presented and claimed herein are referenced and appliedto material objects and concrete examples of a practical nature thatdemonstrably improve the present technical field and, as such, are notabstract, intangible or purely theoretical. Further, if any claimsappended to the end of this specification contain one or more elementsdesignated as “means for [perform]ing [a function] . . . ” or “step for[perform]ing [a function] . . . ”, it is intended that such elements areto be interpreted under 35 U.S.C. 112(f). However, for any claimscontaining elements designated in any other manner, it is intended thatsuch elements are not to be interpreted under 35 U.S.C. 112(f).

1. A rod rotator assembly for an artificial lift system, comprising: ahousing configured to be supported by a carrier of the artificial liftsystem; a top cap configured to rotate relative to the housing, whereinthe top cap is configured to support a polish rod of the artificial liftsystem; and a load cell disposed within the housing, wherein the loadcell is configured to support the top cap, and the load cell isconfigured to output a sensor signal indicative of a load applied by thepolish rod to the housing.
 2. The rod rotator assembly of claim 1,wherein the load cell is configured to output the sensor signal via awired connection.
 3. The rod rotator assembly of claim 1, comprising amain gear non-rotatably coupled to the top cap, wherein the main gear isconfigured to be driven to rotate by a worm gear.
 4. The rod rotatorassembly of claim 3, comprising a bearing disposed between the load celland the main gear.
 5. The rod rotator assembly of claim 1, wherein theload cell is disposed between the top plate and a base of the housing.6. The rod rotator assembly of claim 1, wherein a set of alignmentplates is not disposed within the housing.
 7. A rod rotator assembly foran artificial lift system, comprising: a housing configured to besupported by a carrier of the artificial lift system, wherein thehousing has a base and a body extending upwardly from the base along alongitudinal axis of the rod rotator assembly, the body forms an openingon an opposite longitudinal side of the housing from the base, and theopening provides access to an interior of the housing; a top capconfigured to rotate relative to the housing, wherein the top cap isconfigured to support a polish rod of the artificial lift system, thetop cap has an engagement surface configured to engage a polish rodclamp to support the polish rod, and the top cap has a body extendingthrough the opening in the housing; and a load cell disposed within theinterior of the housing between the body of the top cap and the base ofthe housing along the longitudinal axis of the rod rotator assembly,wherein the load cell is configured to support the top cap, and the loadcell is configured to output a sensor signal indicative of a loadapplied by the polish rod to the housing.
 8. The rod rotator assembly ofclaim 7, wherein the load cell is configured to output the sensor signalvia a wired connection.
 9. The rod rotator assembly of claim 8,comprising a connector coupled to the body of the housing and configuredto establish the wired connection to the load cell.
 10. The rod rotatorassembly of claim 7, comprising a main gear non-rotatably coupled to thebody of the top cap, wherein the main gear is configured to be driven torotate by a worm gear.
 11. The rod rotator assembly of claim 10, whereinthe body of the top cap has a ledge engaged with the main gear, and themain gear is disposed between the ledge of the body of the top cap andthe load cell along the longitudinal axis of the rod rotator assembly.12. The rod rotator assembly of claim 10, comprising a bearing disposedbetween the load cell and the main gear along the longitudinal axis ofthe rod rotator assembly.
 13. The rod rotator assembly of claim 12,wherein the bearing comprises a ball bearing.
 14. The rod rotatorassembly of claim 7, wherein a set of alignment plates is not disposedwithin the interior of the housing.
 15. The rod rotator assembly ofclaim 7, comprising an adapter ring disposed between the body of the topcap and the load cell along a radial axis of the rod rotator assembly.16. An artificial lift system, comprising: a polish rod configured todrive a pump disposed within a reservoir; a carrier configured to becoupled to a pump jack of the artificial lift system; and a rod rotatorassembly, comprising: a housing supported by the carrier; a top capconfigured to rotate relative to the housing, wherein the top cap isconfigured to support the polish rod; and a load cell disposed withinthe housing, wherein the load cell is configured to support the top cap,and the load cell is configured to output a sensor signal indicative ofa load applied by the polish rod to the housing.
 17. The artificial liftsystem of claim 16, wherein the rod rotator assembly comprises a maingear non-rotatably coupled to the top cap, and the main gear isconfigured to be driven to rotate by a worm gear.
 18. The artificiallift system of claim 17, wherein the rod rotator assembly comprises abearing disposed between the load cell and the main gear.
 19. Theartificial lift system of claim 16, wherein the load cell is disposedbetween the top plate and a base of the housing.
 20. The artificial liftsystem of claim 16, wherein a set of alignment plates is not disposedwithin the housing.